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import unittest
import ctypes
import gc
MyCallback = ctypes.CFUNCTYPE(ctypes.c_int, ctypes.c_int)
OtherCallback = ctypes.CFUNCTYPE(ctypes.c_int, ctypes.c_int, ctypes.c_ulonglong)
import _ctypes_test
dll = ctypes.CDLL(_ctypes_test.__file__)
class RefcountTestCase(unittest.TestCase):
def test_1(self):
from sys import getrefcount as grc
f = dll._testfunc_callback_i_if
f.restype = ctypes.c_int
f.argtypes = [ctypes.c_int, MyCallback]
def callback(value):
#print "called back with", value
return value
self.assertEqual(grc(callback), 2)
cb = MyCallback(callback)
self.assertTrue(grc(callback) > 2)
result = f(-10, cb)
self.assertEqual(result, -18)
cb = None
gc.collect()
self.assertEqual(grc(callback), 2)
def test_refcount(self):
from sys import getrefcount as grc
def func(*args):
pass
# this is the standard refcount for func
self.assertEqual(grc(func), 2)
# the CFuncPtr instance holds atr least one refcount on func:
f = OtherCallback(func)
self.assertTrue(grc(func) > 2)
# and may release it again
del f
self.assertTrue(grc(func) >= 2)
# but now it must be gone
gc.collect()
self.assertTrue(grc(func) == 2)
class X(ctypes.Structure):
_fields_ = [("a", OtherCallback)]
x = X()
x.a = OtherCallback(func)
# the CFuncPtr instance holds atr least one refcount on func:
self.assertTrue(grc(func) > 2)
# and may release it again
del x
self.assertTrue(grc(func) >= 2)
# and now it must be gone again
gc.collect()
self.assertEqual(grc(func), 2)
f = OtherCallback(func)
# the CFuncPtr instance holds atr least one refcount on func:
self.assertTrue(grc(func) > 2)
# create a cycle
f.cycle = f
del f
gc.collect()
self.assertEqual(grc(func), 2)
class AnotherLeak(unittest.TestCase):
def test_callback(self):
import sys
proto = ctypes.CFUNCTYPE(ctypes.c_int, ctypes.c_int, ctypes.c_int)
def func(a, b):
return a * b * 2
f = proto(func)
a = sys.getrefcount(ctypes.c_int)
f(1, 2)
self.assertEqual(sys.getrefcount(ctypes.c_int), a)
if __name__ == '__main__':
unittest.main()
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